T. Vijayaraghavan

Tirukkannapuram Vijayaraghavan , mostly cited as T. Vijayaraghavan, (born November 30, 1902 , † April 20, 1955 ) was an Indian mathematician who dealt with analysis .

Life

T. Vijayaraghavan came from a Brahmin family and was Tamil . His father was a well-known Sanskrit scholar ("Pandit"), and Vijayaraghavan was also familiar with Sanskrit and Tamil literature (according to André Weil, he always carried a Mahabharata in Tamil with him). He was a student of K. Ananda Rau at the University of Madras . In the 1920s he studied with Godfrey Harold Hardy at Oxford, but did not receive a formal degree (nor did he at Madras). In 1929 he received his doctorate from Hardy at Oxford (Properties of power series and continued fractions). At that time he could already show several publications. When André Weil was at Aligarh Muslim University from 1930 to 1932 , he brought Vijayaraghavan, who had just returned from Oxford, as an assistant. Weil had a great influence on Vijayaraghavan and became friends with him - Vijayaraghavan also introduced him to Sanskrit literature, which Weil had already started to study in Paris. Another mathematician who sponsored Weil was DD Kosambi (1907–1966). In 1931 Vijayaraghavan left Aligarh Muslim University and went to Dacca University. The reason was that the head of the university secretly wanted to get rid of André Weil, who was just in Paris, and offered Vijayaraghavan his post, which he refused. To avoid conflicts, he went to Dacca University in 1931.

In 1949 he became director of the Ramanujan Institute in Madras, which was then newly founded by Alagappa Chettiar. Another well-known mathematician at the institute was CT Rajagopal (1903–1978), who had received his doctorate from Vijayaraghavan. Due to a lack of funding, it was difficult to establish international contacts at the institute at the time, but it did support young Indian mathematicians such as CP Ramanujam and Raghavan Narasimhan . Vijayaraghavan died relatively young (according to Weil, not least because of his overweight).

At first, like Rau, he dealt with topics from the Hardy School and especially with Borel summation and proved a few sentences of the Tauber type. He refuted an assumption made by Émile Borel about the growth of the solutions to nonlinear ordinary differential equations, which earned him international attention and in 1936 an invitation from George David Birkhoff as a guest speaker at the American Mathematical Society . He also dealt with Diophantine approximations , especially the distribution of the fractional part of for ( , fixed real numbers). This led to the introduction of the Pisot Numbers , sometimes called Pisot-Vijayaraghavan Numbers. ${\displaystyle \alpha \cdot {\beta }^{n}}$ ${\displaystyle n\to \infty }$ ${\displaystyle \alpha }$ ${\displaystyle \beta }$

In 1934 he became a Fellow of the Indian Academy of Sciences.

literature

• Raghavan Narasimhan : The coming of age of mathematics in India. In Michael Atiyah et al. a .: Miscellanea Mathematica , Springer, 1991, pp. 249f

Individual evidence

1. ^ André Weil Apprenticeship of a Mathematician , Birkhäuser 1992, p. 73
2. ↑ According to André Weil, he therefore had problems finding a job. Weil overlooked the Ph. D. at Oxford or it didn't seem to count in his eyes. Vijayaraghavan failed at the tests in Madras after Weil.
3. ^ Mathematics Genealogy Project
4. ↑ Because Apprenticeship of a Mathematician , pp. 70f
5. ↑ He had studied at Harvard, was later at the Tata Institute of Fundamental Research and dealt with differential geometry. Later he was a well-known historian who wrote a book about the Maurya Empire ( Waldschmidt Indo-french cooperation in mathematics , Math Newsletter 2010, pdf , Thapar Early indian history and the legacy of DD Kosambi , 2011, pdf )
6. ^ According to the Mathematics Genealogy Project . Since they were almost the same age, this is unusual. After R. Narasimhan he was a student of K. Ananda Rau , who is listed as a co-referee in the Mathematics Genealogy Project.